Bilateral temporal skull xanthoma characterized as a Langerhans cell histiocytosis: a case report

Xanthomas are benign lipomatous deposits that can be found systemically in various tissues, including bones, in human beings. Their presence in the skull remains a rare entity. Despite their benign characteristics, imaging modalities are often unable to distinguish them from neoplastic lesions. This leads to a diagnostic dilemma in patients with Langerhans cell histiocytosis. This case report highlights such a case, where clinical history and image findings were concordant with that of Langerhans cell histiocytosis in the temporal skull region.

A 32-year-old Han Chinese woman was diagnosed with Langerhans cell histiocytosis. During systemic workup for her tumor, she was found to have bilateral temporal lesions. Magnetic resonance imaging of the brain, as well as a computerized tomography scan, were consistent with that of Langerhans cell histiocytosis. As treatment would be drastically affected by the diagnosis, an excision biopsy was performed. The histology was dramatically inconsistent with that of a bone xanthoma.

Xanthomas are benign lesions that can be seen deposited in appendicular and axial skeleton. Lesions are rare, with most case descriptions focusing on their presence in the mandible and temporal bone. They usually have a benign course but may present with symptoms due to localized mass effect. Surgical intervention and histologic diagnosis may still be required in these lesions owing to the lack of imaging characteristics that confirm their diagnosis through noninvasive methods.